Machine vision is the aspect of industrial automation that deals with capturing images of objects with cameras, in digital form, and using the information in the image to guide industrial processes. Such devices are typically used to locate patterns for alignment, to measure distances, angles and other critical dimensions, to guide robots, to inspect the quality of manufactured items, and to identify unknown objects. The digital image processors upon which machine vision devices are built must perform a variety of computations rapidly, efficiently and inexpensively to be practical elements in industrial automation.
Image analysis systems extract information from raw or processed video images and generate information or decisions regarding the images. An earlier patent assigned to the assignee of this invention, U.S. Pat. No. 4,972,359, describes a coprocessor that provides certain image analysis computations efficiently.
Image processing systems manipulate the pixels of a raw video image through such processes as filtering, subtraction and rotation, and generate another, enhanced, image as output. The operations include grey scale morphology, grey scale edge detection, and rank value filtering.
Some of these functions are provided individually in the prior art by particular chips, such as a rank value filter available from LSI Logic as the L64220, a cartesian to polar conversion chip available from Plessey Semiconductors as the PDSP16330, and an edge detection chip available from Plessey Semiconductors as the PDSP16401.
The object of the invention is to combine and improve image processing devices and methods in a unique and efficient arrangement that provides great flexibility in responding to image processing needs, and that provides for a unique and efficient relationship with the rest of a machine vision system.